//
// Created by Asus on 2025/6/2.
//

#include <iostream>
#include <string>
#include <bits/ostream.tcc>
using namespace std;

void demo01() {
    string str1 = "我";
    str1 += "爱玩游戏";
    cout << "str1: " << str1 << endl;

    str1 += ":";
    cout << "str1: " << str1 << endl;

    string str2 = "LOL DNF";
    str1 += str2;
    cout << "str1: " << str1 << endl;

    string str3 = "I";
    str3.append(" love ");
    str3.append("game :LOL DNF", 4);
    cout << "str3: " << str3 << endl;
    str3.append(" ==== ", 1,4);
    cout << "str3: " << str3 << endl;
}

int main(int argc, char *argv[]) {
    demo01();
    return 0;
}
